Inspection Procedure G-3

Windshield Wiper Motor Driver Circuit:

CIRCUIT OPERATION
A signal from the windshield wiper switch is sent through the column-ECU inside the column switch to the front-ECU. The signal turns on the relay inside the front-ECU to
operate the wiper motor.

TECHNICAL DESCRIPTION (COMMENT)
The wiper motor or the front-ECU may be defective.

TROUBLESHOOTING HINTS
- Malfunction of the wiper motor
- Malfunction of the front-ECU
- Damaged harness wires and connectors

DIAGNOSIS
Required Special Tool:
MB991223: Test Harness Set




STEP 1. Check the windshield wiper motor
1. Disconnect the wiper motor connector A-03.
2. Run the wiper motor at low-speed, disconnect the battery, and stop the motor.
3. Reconnect the battery as shown in the illustration, and confirm that after the motor starts turning at low-speed, and stops at the automatic stop position.
If the wiper motor is damaged, replace the wiper motor. The windshield wiper should stop at the predetermined park position.
If the wiper motor is in good condition, go to Step 2.




STEP 2. Check the wiper motor power supply circuit at the wiper motor connector A-03.
1. Disconnect the wiper motor connector A-03 and measure at the harness side.
2. Turn the ignition switch to "ACC" position.
3. Voltage between terminal 1 and ground.
- Voltage should be approximately 12 volts (battery positive voltage).
If not approximately 12 volts, go to Step 3.
If approximately 12 volts, go to Step 5.




STEP 3. Check the wiper motor connector A-03 for damage.
If the wiper motor connector A-03 is damaged, repair or replace it. Refer to Harness Connector Inspection.
The windshield wiper should stop at the predetermined park position.
If the connector is in good condition, go to Step 4.










STEP 4. Check the harness wires between wiper motor connector A-03 and ignition switch (ACC).

NOTE: After checking intermediate connector C-94 and junction block connector C-101 and C-109, check the wires. If intermediate connector C-94 and junction block connector C-101 and C-109 are damaged, repair or replace them. Refer to Harness Connector Inspection.

If the harness wires between wiper motor connector A-03 and ignition switch (ACC) are damaged, repair or replace them.
The windshield wiper should stop at the predetermined park position.







STEP 5. Check the wiper motor connector A-03 and front-ECU connector A-09X for damage.
If the wiper motor connector A-03 and front-ECU connector A-09X are damaged, repair or replace them. Refer to Harness Connector Inspection.
The windshield wiper should stop at the predetermined park position.
If the connectors are in good condition, go to Step 6.










STEP 6. Check the harness wires between wiper motor connector A-03 and front-ECU connector A-09X.

NOTE: After checking intermediate connector C-06, check the wires. If intermediate connector C-06 is damaged, repair or replace it. Refer to Harness Connector Inspection.

If the harness wires between wiper motor connector A-03 and front-ECU connector A-09X are damaged, repair them. The windshield wiper should stop at the predetermined park position.